Esser



(No Model.)

J. WEIDENMANN.

T-SQUARE.

No. 282,248. Patented July 31. 1883...

1 WITNESSES: 11.;193

ATTORNEY UNITED STATES FATENT OFFicE.

JACOB WEIDENMANN, on New, YORK, N. Y., ASSIGNOR TO KEUFFEL &

a ESSER, or SAME PLACE.

T-SQUARE.

SPECIFICATION forming part .of Letters Patent No. 282,248, dated July 31, 1883.

Application filed March 24, 1882. {No model.)

To aZL whom, it may concern:

Be it known that I, JACOB WEIDENMANN, of the city, county, and State of New York, have invented certain new and useful improvements in T-Squares, of which the following is a specification.

This invention relates to an improved construction of a T-square used by architects,'engineers, and draftsmen generally, the improvements being designed to relieve the body from the physical strain caused by stooping over the board, and to obviate the foreshortening of the lines and figures on the-board when the same fall into an oblique position from the stand-point of the designer, so that the work of the draftsman is facilitated and rendered more agreeable and accurate.

The. invention consists of a T-square, the blade of which is provided with a raised longitudinal guide-rib near the center of the blade, and with a second longitudinal rib near the lower edge of the same, while between the ribs an intermediate opening or openings for holding a pencil, eraser, or other article, are arranged.

In the accompanying drawings, Figure l represents a perspective view of a drawing board with my improved T-square. Fig. 2 is a top view; Fig. 3, a vertical transverse section of the same on line 00 m, Fig. 2. Fig. 4

is a vertical longitudinal section on line y Fig. 2; and Figs. 5 and 6 are vertical transverse sections through the head of the T- square, respectively, on lines f f and c c, Fig. 2. Similar letters of reference indicate corresponding parts. l Referring to the drawings, A represents th head, and B the blade, of my improved T- square. The T-squar'e is especially designed to be worked with a drawing-board which is not supported in a horizontal or slightly-inclined position, but which is supported in nearly upright position, as shown in Fig. 1.

To use the T-square with advantage on a drawing-board supported at such an inclination, the head of the T-square is provided with suitable adjusting and clamping means whereby the T'square may be readily retained at any point of the board, wherever it may be required by the draftsman, the adjustment being made in such a manner as not to impede or obstruct the quick, convenient, and accurate use of the T-square. For this purpose a guide-strip, G, is secured, by means of a suitable fastening, e, to the left-hand side of the drawing-board, the guide-strip serving as a guide along which the head of the T-square is moved. 7 The strip 0 is provided with a.

longitudinal groove of any suitable cross-section, for guide tongues or runners b, secured to the under side of the head A of the T- square. A friction stop or clamp, D,is arranged in a recess between the tongues 12, at the middle portion of the head A. The fric. tionclamp D is pressed tightly against the guide-strip O by means of a strong spiral spring,e. The friction-clamp D is released, so as to admit the adjustmentof the Tsquare, by means of aslide-button, d, which is connectedby a pivot-pin, d, to the friction-clan1p at its opposite end.

The parts so far described have been used heretofore, and I do not claim the same.

By these means the T-square is securely retained at any desired point on the drawingboard, andquickly and conveniently adjusted.

The blade of the T-square is provided with two longitudinal ribs, ffone near the middle of the blade and the other near the lower edge of the sameas shown clearly in Figs. 1 and 2. The body of the blade between the ribs ff is provided with openings f, Fig. 2. The, uppermost rib f serves as a guide for the little finger of the right hand, so as to steady the pencil or drawing-pen. The lower rib f andthe intermediate opening, f, serve to. hold the pencil, eraser, or similar articles used by the draftsnian, so as to have them always handy for use. The ribs serve to strengthen the body of the T-square,while the openingsdecrease the weight of the same.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1'. In a T-square, ablade provided with a longitudinal rib near the lower edge of the T- square, and with openings in the'body of the blade above said rib, substantially as and for In testimony that I claim the foregoing as my the purpose set forth. invention I have signed my name in presence 2. In a T-square, a blade provided with of two subscribing Witnesses. longitudinal ribs-one near the center and the J AOOB WVEIDENMANN. 5 other near the lower edgeand with interme- WVitnesses:

diate openings between the ribs, substantially PAUL GOEPEL,

as and for the purpose set forth. SIDNEY MANN. 

